温轧Fe-3%Si钢带的显微结构及取向行为表征

发布时间：2018-03-18 02:38

  本文选题：温轧　切入点：Fe-3%Si　出处：《沈阳化工大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文以Cu_2S和MnS为主要抑制剂,以含硅3%的取向硅钢为材料,进行不同温度的温轧试验,通过金相、EBSD、XRD和TEM等手段研究热轧、温轧、初次再结晶退火和二次再结晶退火各个工艺阶段的组织、织构和析出物的演化规律。用磁性能检测仪对四种温轧温度的二次再结晶退火后的钢带进行磁性能检测,根据硅钢低铁损和高磁感的性能要求优化出合理的温轧工艺参数,为高性能电工钢带的开发提出新的方法和途径,实现绿色化,低成本,高性能取向硅钢的开发。本文得出的主要结论如下:(1)取向硅钢热轧板沿厚度方向的组织不均匀,表层晶粒的平均尺寸为30μm,形状为等轴晶;过渡层和中心层为拉长的铁素体晶粒和带状的碳化物,其平均晶粒尺寸为15.8μm。温轧后,表层和中心层均为纤维状组织。温轧板初次再结晶组织均为细小的等轴晶,沿厚度方向的表层晶粒比中心层晶粒细小。二次再结晶退火之后,初次再结晶组织发生异常长大。50℃、100℃、200℃和300℃温轧试样的二次再结晶组织平均晶粒尺寸分别为3.5mm,2.3mm,4.5mm和3.8mm。(2)随着温轧温度的增加,取向硅钢成品板铁损值逐渐增加,磁感值先增加后减小,在200℃温轧样品中达到最大值。50℃温轧时成品板磁感应强度和铁损分别为B8=1.711T,P1.7/50=2.975W/Kg;200℃温轧时磁感应强度和铁损分别为B8=1.780T,P1.7/50=3.229W/Kg。(3)50℃、100℃、200℃和300℃四种不同的温轧板均以α(110//RD)织构为主,最强点为{001}110,同时也存在较强的γ(111//ND)织构,且表层比中心层强。初次再结晶退火后,α织构显著减弱,γ织构成为主要部分,且出现了较弱的Goss({110}001)织构。整体而言,50℃和200℃温轧时,α和γ织构强度最强。(4)热轧板中小角晶界与大角晶界的比例约为3:2,温轧板中小角晶界与大角晶界的比例增加至约3:1,其中Σ3~Σ11重位点阵晶界占有的比例较高。(5)热轧时随着温度的降低,MnS先析出,随后Cu_2S析出,热轧板中主要以Cu_2S和MnS复合的形式析出,平均尺寸约为43nm,分布密度约为1.5×109个/cm2。温轧板中同样存在Cu_2S和MnS的复合析出物,而且在50℃温轧板出现了少量的AlN析出。初次再结晶退火板中存在细小弥散的Cu_2S和MnS析出物,平均尺寸约为52.9nm,分布密度约为2.5×1010个/cm2,相对于热轧板,析出粒子尺寸增加且更均匀,晶粒长大抑制能力较强。
[Abstract]:In this paper, Cu_2S and MnS were used as the main inhibitors, and silicon 3% oriented steel was used as the material. The hot rolling and warm rolling were studied by means of metallography, EBSD, XRD and TEM. The microstructure, texture and evolution of precipitates in the first recrystallization annealing and secondary recrystallization annealing. The magnetic properties of the steel strips after secondary recrystallization annealing at four temperature rolling temperatures were measured by magnetic property tester. According to the requirements of low iron loss and high magnetic inductance of silicon steel, reasonable warm rolling process parameters are optimized, and new methods and approaches for the development of high performance electrical steel strip are put forward to realize green and low cost. Development of high performance oriented silicon steel. The main conclusions obtained in this paper are as follows: (1) the microstructure of the hot rolled plate of oriented silicon steel along the thickness direction is not uniform, the average grain size of the surface layer is 30 渭 m and the shape is equiaxed. The transition layer and the center layer are elongated ferrite grains and banded carbides with an average grain size of 15.8 渭 m. After warm rolling, both the surface and center layers are fibrous, and the primary recrystallization structure of the warm rolled sheet is both fine equiaxed. The grain size in the surface layer along the thickness direction is smaller than that in the central layer. After secondary recrystallization annealing, The average grain size of the secondary recrystallization microstructure of the primary recrystallized specimens grown abnormally at .50 鈩，

本文编号：1627660